The present invention relates to a process for drying wet coal and particularly sub-bituminous coal of the type that, as mined, would have about thirty percent moisture. More particularly, the invention relates to the drying of coal having a size of two inches or less wherein the heat for dyring the coal is provided by exothermic oxidation in air at temperatures of about 180.degree. to 200.degree. F. and not greater than 250.degree. F.